Hi,
If you edit the custom field via the Display>Custom fields menu, you have the setting "Back-end Listing" that you can activate and the custom field value will appear on the listing without any code modification to order / listing.php
Now this will display the value of the custom field, not the input field. If you want the input field, it will require coding. First in order / listing.php to add the HTML of an input field, and then add a controller via a hikashop plugin to be able to save the data in the custom field column in the database.